think of it like this, the smaller gear has to turn many more times to get the larger one to turn once.
lets say you have a 5:1 ratio, the first gear has to turn 5 times to get the back one to turn once. of course the more times you turn the first gear to get the second to turn once, the lower the ratio and the more/ better acceleration you get.
hope this makes sense... i know you have already figured that the lower top speed you have the more acceleration, vice versa.
EDIT: 2 piece lock collar meaning theres 2 half circle pieces that bolt together, so you can put them on without taking your torque converter apart.